Apparatus for handling concrete blocks



July 8, 1947. R. M. GRAY APPARATUS FOR HANDLING CONCRETE BLOCKS 10 Sheets-Sheet 1 Filed April 10, 1944 ROBERT M. GRAY i INVENTOR 1 ATTORNEY July 8, 1947. R. M. GRAY APPARATUS FOR HANDLING CONCRETE BLOCKS Filed April 10, 1944 10 sneaks-sheet 2 a 2 Q a 2 L .\t.\ N 2 R. v \mN\ a: w $3 \U \H Tum N N\. Q |l rl llZl -uLrlW. llil N. I T.. Jill; L rlll lL M ulllL r l |m milllm mil ..|l.l|- o LBW- F L: L FL a an rliizl whl; IL Film Q RUBERTMQGRAY July 8, 1947. R. M. GRAY 2,423,557

APPARATUS FOR HANDLING CONCRETE BLOCKS Filed April 10, 1944 10 Sheets-Sheet 3 B v q a? IF? I I I I u i I '1 1 o! 102 i Q: 55 72 1a 60 E s e 6 i m 4' 5 3 r:

I I v 1. m Li I I 5' 1 I ma L1 I1 ,111 ,07 104 4 1 a l I 2 l al I l I l l l r I I RUB E-RT M.G'RAY ATTORNEY July 8, 1947. R. M. GRAY APPARATUS FOR HANDLING CONCRETE BLOCKS Filed April 10, 1944 10 Sheets-Sheet 4 RUBERT MBRAY July 8, 1947. R. M. GRAY 2,423,557

APPARATUS FOR HANDLING CONCRETE BLOCKS 3 ROBERT MQBRAY a INVENTOR ATTORNEY R. M. GRAY APPARATUS FOR HANDLING CONCRETE BLOCKS Filed A ril 10, 1944 10 Sheets-Sheet 6 ROBERT WLBRAY INVENTOR ATTORNEY- July 8, I947.

July 8, 1947. R. M. GRAY APPARATUS FOR HANDLING CONCRETE BLOCKS Filed April 10, 1944 10 Sheets-Sheet 7 ROBERT TYLBF'AY INVENTOR ATTORNEY July 8, 1947. R. M. GRAY 2,423,557

APPARATUS FOR HANDLING CONCRETE BLOCKS Filed April 10,1944 l0 Sheets-Sheet 8 R DB ERT. 1Y1. GRAY INVENTOR 10 Sheets-Sheet '9 R. M. GRAY Filed April 10, 1944 APPARATUS FOR HANDLING CONCRETE BLOCKS l l L I I I I.-- I.-- I.-- 1-- i.-- l i:

INVENTOR RUBERTML; RAY

July 3,1947. R. M. GRAY 3,557

. v APPARATUS FOR HANDLING CONCRETE BLOCKS Filed April 10, 1944 10 5heets-Shoet 10 R n H ER T m. GRAY INVENTOR ATTORNEY Patented July 8, 1947 APPARATUS FOR HANDLING CONCRETE BLOCKS v Robert M. Gray, Shemeld, Ala. Application April 10, 1944, Serial No. 530,339 13 Claims. (01. 21418) This invention relates to apparatus for handling and curing molded concrete products, particularly concrete building blocks as they come, freshly molded, from the block making machine, and has for its principal object the provision of apparatus of the character designated which shall be effective to reduce breakage to a minimum and eliminate the necessity of manual handling of the blocks until set and cured.

A further object of my invention is to provide apparatus for loading concrete blocks on racks in multiple layers as they come from the block making machine, together with a continuous kiln for the racks, means for conveying the racks through the kiln, and means for unloading the racks after they have passed through the kiln and for returning them to their initial station for re-loading.

A further object of my invention is to provide, in association with a concrete block making machine, a continuous circular kiln for curing the concrete blocks, a rotary support in the kiln, a multiplicity of racks for the blocks adapted to be carried around the kiln on the support, and mechanism operative responsive to movement of the blocks from the block making machine for loading and unloading the racks and for operating the rotary conveyor.

A still further object of my invention is to provide, in apparatus of the above mentioned character, racks each having a plurality of superposed shelves, and in which the shelves are loaded and unloaded, one at a time, by the mechanism responsive initially to movement of blocks from the block making machine.

In the art to which my invention relates, concrete blocks are molded by a machine, and as molded are placed automatically on pallets and delivered from the machine. It has heretofore been the practice to remove these pallets one at a time as they come from the machine, by means of an air hoist and place the pallets on racks leading a rack and showing the rack loaded and having wheels thereon which are pushed by hand I into akiln and cured. When the blocks are cured, the racks are removed from the kiln, and are unloaded by another hoist, and the pallets returned to the block making machine. It is well known that freshly made concrete blocks are relatively fragile and that in the handling of the blocks in the manner described, pallets are sometimes dropped, rough places over which the racks may be moved cause them to be jostled and jarred, and carelessness or workmen all combine to prolduce a high percentage of breakage. In the practical operation of a block making plant, I have experienced a loss due to breakage as high as twenty five percent. Besides the loss due to breakage, the labor cost of handling the blocks in the manner described is excessive. It is accordingly the principal object of my invention to provide. a machine for handling the blocks as they come from the block making machine which will load the pallets on the racks, propel the racks through a. circular kiln and unload them as they complete their circuit of the kiln, without any manual handling of the blocks or the racks.

In the accompanying drawings forming a part of this application,

Fig. 1 is a plan view showing the general arrangement of a circular kiln having my improved block handling mechanism associated therewith;

Fig. 2 is a fragmentary sectional plan view of the kiln drawn to an enlarged scale, showing the places of loading and unloading the racks and showing somewhat diagrammatically the machines associated therewith;

Fig. 3 is a side elevation of a unit adapted for in raised position;

Fig. 4 is a sectional view taken along the line IV-IV of Fig.

Fig. 5 is a sectional plan view taken along the line V--V of Fi 4;

Fig. 6 is a side elevation, drawn to an enlarged scale, with parts broken away, showing details of the conveyors embodied in the loading and unloading machines;

Fig. '7 is a fragmentary plan view showing details of the conveyors and with the shuttle conveyor beginning its return travel after loading or unloading a rack;

- Fig. 8 is a detail view showing mechanism for moving the circular support on which the racks are carried through the kiln, and showing the plunger of the hydraulic cylinder in retracted position; I I

Fig. 9 is a wiring diagram of the controls for the motor operating the conveyors of the loading machine;

Fig. 10 is a side elevation of the loading machine showing the rack in its lowest position at the beginning of the loading operation, together with a diagrammatic showing of the hydraulic controls for operating the apparatus;

Fig. 11 is a wiring diagram of the controls for the magnetic valves employed with the hydraulic cylinders in/the loading operation;

Fig. 12 is 9, vertical sectional view of a typical three-way magnetic valve for controlling a hydraulic cylinder in accordance with my invention: V

Fig. 13 is a sectional view of the valve shown in Fig-l2 taken at right angles to the showing in Fig. 12;

Fig. 14' is a sectional view of a typical one-way valve associated with the hydraulic cylinders;

Fig. 15 is a view similar to Fig. 8 showing the mechanism for imparting intermittent motion to the circular support on which the racks are carried in the kiln and showing the plunger in extended position;

Fig. 16 is a view similar to Fig. 10 showing the unloading machine with the rack in its highest position at the beginning of the unloading operation, together the hydraulic controls for operating the apparatus; and

Fig. 1-! is a wiring diagram of the controls for the magnetic valves and motor employed with the hydraulic cylinders in the unloading operation. 4

Referring to the drawings. I show diagrammatioally in Figs. 1 and 2 a block making machine I0 which may be of any well known design adapted to mold concrete blocks and deliver them from the machine on pallets P. A chain type conveyor I? is included in the blockmakingmachine for conveying the pallets out of the machine. At 13 I show a circular kiln for curing the blocksand disposed within the kiln is a circular rotary support i4 comprisedof concentric rails l6 and i1 joined together by suitable cross members 3. The rails I6 and I! rest on rollers l9 and 2K Fig. 3) which QaLre suitably journalled at the. sides beneath the rails so that the track may be rotated on the rollers within the kiln. Supported by the cross members l 8 are a plurality of racks 22 each constructed from vertical frame members 23 and is joined along the side by lateral frame members 26 forming a plurality of superposed shelves 2? upon which the loaded pallets P are adapted to rest and be carried through the kiln by rotation of the rotary support M. .It is contemplated that the kiln shall be of such dimensions that the racks.

22 may be loaded one at a time as the pallets are delivered from the block making machine it, and that by the time a rack has "completed its rotation around the circular kihi. and arrived back at its starting position, the blocks will be completely cured and ready for use. As each rack is frame members 41 and 48.

able means, not shown, where the blocks are removed by means of a suitable air hoist l4 and crane 36.

The loading and unloading machines 3| and 32 are identical. in construction, but operate in a reverse order. A description of the construction of one of the machines will accordingly serve for both except for. the operating controls thereof. The loading machine 3|, shown in Figs. 3 to 7 inclusive, comprises a frame having outer vertical members 31 on one side and 38 on the other side which are Joined, together at the rear by a transverse channel39 and at the front by a transverse channel There are also inner vertical frame members 42 and 43 (see Figs. 4, 5 and 7) which are joined to the transverse members and to the outer vertical frame members by diagonal braces 44 and 46. Supported on the inner vertical members 42 and 43 are stationary conveyor Mounted between the vertical members 31 and 42 at both front and rear are stub shafts 49 and 5| having smooth disks 52 and 59 mounted on their inner ends. Mounted between the vertical members 36 and 43 at both front and rear are stub shafts 54 and 56 which also have smooth disks 51 and 58 mounted on their inner ends. Conveyor chains 55 and Snare passed over the disks 52 and 53 and 61 and 58 to form means for supporting and moving the pallets P from the concrete block making machine.

. Disposed between the side frame members 41 and 48 of the stationary conveyor is a movable, or shuttle conveyor comprised of side members 59 and Bi braced by diagonal struts 49 and having shafts 62' and 63 mounted in plates 64 and t6 secured to the side frame members at the rear end, and in plates 61 and 68 secured to the side frame members 59 and 6| at the forward ends loaded and placed on the rotary support l4, mo-

tion is imparted to the support by means of a hydraulic cylinder 28 which is adapted, in a manner to be described later, to move the support the -width of one rack at a time.

The kiln I3 is provided with an opening 29 through which the racks 22 are loaded and unloaded, and disposed between the block making machine l0 and the opening is my improved loadin machine 3| which is adapted to load the racks 22 in response to the delivery of loaded pallets P from the block making machine i0, and to place the racks on the rotary support M. A similar machine 32 is disposed in front of the opening 29 to unload the racks one at a time after they have passed around the kiln, and to deliver the pallets to a roller conveyor 33 driven by any suittransverse members 39 and 4!.

thereof. Mounted on the ends of the shafts 62 and 93 are smooth disks 69 and II respectively over which conveyor chains 12 and 13 run. The shuttle conveyor is supported by means of diagonal channels 14 and 16 which are secured to the side frame members 59 and 6| and which extends downwardly. See Figs. 3 and 4. Mountedacross the channels .14 and 16 are shaft 11 and I8, the upper shaft 11 having flanged rollers I9 and 8! thereon and the lower shaft 19 having'similar rollers 82 and 83 thereon. The wheels 19 and Si bear respectively on the upper surfaces of I beams 84 and 86 and the wheels 82 and 93 bearrespectively against the lower surface of said I beams so that the movable conveyor can be reciprocated. The I beams 84 and 86 are secured to the inner vertical frame members 42 and 43 and to the As may be seen from a consideration of Figs. 3 to '7 inclusive, the shuttle conveyor can be moved rearwardly to assume a position between the side members 41 and 43 of the stationary conveyor.

Referring particularly to Fig. '4, both the stationary and the shuttle conveyors are driven in unison from a motor 81 suitably supported on top of the stationary conveyor frame. Embodied in the casing of the motor is a magnetic brake 88 which is released when energized but which prevents rotation of the motor when deenerg'ized. The motor 81 drives the conveyors through a reduction gear assembly 89 and a drive shaft 9 i connected by a sprocket and chain 92 with a sprocket 93, mounted on a shaft 94, extending across the frame and supported in suitable bearings 96 and 91, mounted in the vertical'members 31 and 38. Mounted on the shaft 94 are sprockets 33 and 03, which are connected by means of chains IN and I02 to sprockets links of the sprocket chain 35 of the stationary conveyor and a toothed sprocket II4adapted to mesh with the links of the sprocket chain 12 or the shuttle conveyor. Near the inner end of the shaft I01 is a. toothed sprocket II3 adapted to mesh with the links of the sprocket chain 30 of the stationary conveyor.- On the extreme ln-. ner end of the shaft I01is a toothed sprocket 1 adapted to mesh with the links of sprocket chain 13. The chains of both the stationary and the shuttle conveyor are thus driven in unison from the motor 31 and the'conveyor chains are free to slip, if necessary, on the smooth disks over which they run.

The shuttle conveyor is reciprocated by means of a hydraulic cylinder III suitably supported between the frame members of the stationary conveyor and having its plunger 3 connected to the forward end of the shuttle conveyor at I2I. The wheels 13, BI, 32 and 33 being mounted to bear against the upper and lower surfaces of the I beams 34 and 33, permits the extension and retraction of the shuttle conveyor. 1

When the shuttle conveyor is in its extended position, as shown in Figs. 3' and 5, it is-in position to load the pallets P with their'concrete blocks on to the rack 22. Mounted in the opening 29, in front of the loading machine 3i is a hydraulic hoist comprising a cylinder I22 and plunger I23. A-plunger head I24 is provided at its sides with supporting members I23 and I21 which are adapted to straddle the side frame members 53 and 3i of the shuttle conveyor to engage and support the racks 22 with consider able clearance between the head I24 and the side frame members. As shown in Fig. 3, the

and is lowered by gravity. Fluid is admitted to the lower end of the cylinder I22 of the load ing machine 3i by means of a magnetically oper-= ated valve IVI through conduit I20 and is exhausted therefrom by means of a branch conduit I20 and a magnetically operated valve W2. The cylinder 22 of the unloading machine 32 has fluid admitted thereto from a. corresponding magnetic valve iV4 through conduit I30 and exhausted therefrom through a magnetically operated valve IV3 and branch conduit I35. See Fig. 16.

Examples of the construction of suitable ma netically operated valves are shown in Figs. 12, 13 and 14. The 3-way valves, such as may be employed for operating the track cylinder 2e and the shuttle conveyor cylinder II8 are shown in Figs. 12 and 13. Each comprises a housing I33 to which fluid is admitted under pressure through a conduit connection I34. Two spring pressed valves I33 and I31 are located within the housing and control the flow of fluid through outlets I33 and I33. The outlet I39 has connected thereto a conduit leading to its associated hydraulic cylinder such as I23 and me, while the outlet I30 leads to the exhaust. Mount ed in the housing I33 is a lever I4I pivoted at I42. The stems of the valves I36 and E31 bear in notches I43 and I44 in the upper and lower surfaces respectively of the lever MI. The opposite end of the lever MI is connected to the lower end of a core I43 of a solenoid I41 mounted on the casing I33. When the solenoid I41 is energized, the lever I is raised, opening the valve I34 and closing the valve I31 so that fluid under pressure is admitted through the valve I36 to pass outwardly through the connection I33 to the cylinder with which the valve is connected; When the solenoid is deenergized. the core I43 returns to'its normal down position shown in Fig. '12, in which valve I31 is opened and valve I36 closed. In this position, fluid passes from the cylinder through the connection I39 and valve I31 to the exhaust I33. The valve shown in Fig. is an example of a suitable valve which rack 22 is in its highest position with all of the to rest on the rotary support I4 and be carried 7 around the kiln I3.

The operation of myimproved block handling apparatus is controlled by means of a system of magnetically operated hydraulic valves and electrical switches and relays which will now be described. The rotary support operating cylinder 28 has a suitable hydraulic fluid admitted alternately to opposite ends thereof by means of magnetically operated 3-way valves 3V2 and 3V3 connected by conduits I28 and I29 to opposite ends of the cylinder. The hydraulic cylinder Iii which actuates the shuttle conveyor on the loading machine 3i has a suitable fluid admitted alternately to opposite ends thereof by means of magnetically operated 3-way valves 3VI and 3V4 through conduits I3I and I32. See Fig. 10. Similar valves 3V5 and 3V6 admit fluid alternately to the hydraulic cylinder Ila operating the shuttle conveyor on the unloading machine 32. See Fig. 16. The hoisting cylinder 22 has its plunger I23! raised by fluid under pressure may be employed with the cylinder I22 and comprises a valve housing I48 having located therein asingle valve I49 which is connected to the lower end of a core IBI of a solenoid I52 mounted on the casing. When the solenoid I32 is energized the valve I49 is opened. When the solenoid is de-energized, the valve moves to its down or closedposition, shown in Fig. 14.

The electrical controls for the loading machine 3| will now be described having reference particularly to Figs. 8, 9, 10 and 11. The source of electrical energy is shown at Ll .L2 and L3. A switch LSI (see Fig. 6) is located on the stationary conveyor in position to be engaged and closed by the pallets P being delivered from the conveyor I2 oi the concrete block making machine. As each pallet closes the switch LSI, it completes a circuit'through relay CRI which energizes a magnetic coil I53, which in turn closes switch LC to the motor 81. The motor 81 starts the stationary and shuttle conveyors in operation as hereinbefore described to advance the first pallet, indicated in Fig. 9 as PI. The relay CRI may have a member I50 associated therewith to delay immediate re-opening of the circuit as soon as the pallet passes over the switch LSI. This provides a slight time interval between the opening of the motor circuit when the brake 08 stops the motor 31 and the conveyors. The operation described is repeated until five pallets have been delivered from the block making machine. When 7 the fifth pallet is delivered, pallet PI will have assumed a position to close a switch LS2 located alongside the stationary conveyor. This switch completes a circuit from LI through relay CR2 which in turn completes the circuit through the magnetic coil I53, closing motor switch LC and again starts the motor 81. Associated with the relay CR2 is a member I54 which is adapted to hold the relay closed and maintain the motor 81 in operation until all five of the pallets have been delivered to the outer end of the shuttle conveyor. q

At the outer end of the shuttle conveyor is a switch LS3 in position to be engaged and closed by the first pallet, PI, arriving at the outer end of the shuttle conveyor. When the switch LS3 is closed, it completes a circuit through a relay CR8 which in turn controls a magnetic coil I55 which is adapted to operate a switch LS4 which completes a circuit through the magnetically operated valve IVI and admits fluid under pressure to the lower end of the cylinder I22. Carried by the plunger head I24 is a downwardly extending arm I51 having notches I58 therein at intervals corresponding to the distance between the shelves 21 of the rack 22 and the distance necessary to raise the rack at the beginning and ending of the loading operation to clear the shuttle conveyor. A stem I59 of the switch LS4 is adapted to be engaged in one of the notches I58 when the switch 154 is open. A spring I5I moves the switch towards opening position when the coil I55 is de-energized. Thus, the closing of the switch LS4 by energizing the coil I55 causes the plunger I23 of the cylinder I22 to be raised, raising the rack 22. As the rack is raised," the switch LS3 opens by disengagement of the pallet PI therewith, but the switch LS4 remains closed due to the fact that the stem I59 is out of a notch I58 and is sliding on the arm I 51. The switch LS4 will thus remain closed until the next notch I58 is reached when the spring I5I will force the stem I55 into the notch and open the switch.

The operation described is repeated until all of the shelves 21 of the-rack 22 have been loaded. It will be noted that the lowest notches I58 on the arm I51 are relatively close together so that the rack 22 is raised only suflicient distance in its last upward movement to clear the pallets off the shuttle conveyor. As the arm I51 approaches its last upward movement a trip I52 on the side thereof opposite the notches I58, engages and closes the switch LS5 which completes the circuit through magnetic valve 3V! (see Fig. 11) admitting fluid under pressure to the forward end of hydraulic cylinder II8 which causes the plunger II9 to move inwardly telescoping the shuttle conveyor back into the stationaryconveyor and clear of the rack 22.

As the shuttle conveyor reaches its most rearward position, it engages and closes a switch LS5 which completes a circuit through a double throw switch LS1 to the magnetically operated valve IV2 which opens and allows the hoist with its loaded pallets to be lowered by gravity on to the rotary support I4 to the position shown in Fig. 10.

the rotary support may be turned. As the hoist moves to its lowest position the head iMengages and moves double throw switch LS1 to its lowest position to complete the circuit to magnetic valve 3V2 admitting fluid under pressure to the cylinder 28 to impart rotary motion to the rotary support I4. The. cylinder 28 has a plunger I52 with a The plunger head I24 continues to move; downwardly until it is clear of the rack so that pivoted head I 53 thereon adapted to engage a cross member I8 and impart movement to the rotary support during outward movement of the plunger, but to pivot out of the way to the dotted position of Fig. 8 as the plunger I52 is retracted. In order that the rotary support may be accurately positioned each time it is advanced, I connect to the side of the cylinder 28 a conduit I354 which is spaced from the end of the cylinder a distance slightly greater than the width of one of the cross members I8 on the rotary supportuThe conduit I54 leads to a cylinder 185 having a plunger I51 therein adapted to engage a cross member I8 on the rotary support I4 but which is normally pushed downwards out of the way by means of a spring I58. When fluid .is admitted to the cylinder 28 to force the plunger I52 outwardly. the leading cross member I5 is first moved over the plunger I 51. When the plunger I52 has advanced an amount suflicient for fluid to be admitted to the conduit I54 and cylinder I55, the plunger I51 is forced outwardly to engage the next succeeding cross member I8 and thus position the rotary support I4 accurately so that the succeeding rack 22 is properly positioned over the hoist members I25 and I21.

When the plunger I52 reaches its outermost position, it engages and closes switch LS8 which in turn completes a circuit energizing relay CR5, which completes a circuit through magnetic valve 3V3 admitting fluid to the opposite end of cylinder 28 to return the plunger I62 to its inner position. The relay CR5 also clossa circult'to magnetic valve IVI through switch LS4, admitting fluid under pressure to the lower end of cylinder I22 and raising the hoist the distance between the first two notches I58 on the arm When the stem I59 drops into the second notch I58, switch LS4 is opened, stopping the hoist in position for the upper shelf 21 of the rack 22 to be loaded by the shuttle conveyor.

As the hoist and rack are raised the distance just described, a trip I58 0n the member I21 engages and closes the switchLSll which completes a circuit to magnetic valve 3V4 admitting fluid under pressure to the rear end of hydraulic cylinder IIB thus moving the shuttle conveyor to its outermost position in the rack 22 to again begin loading the rack.

When the rotary support I4 has been moved one step .by the plunger I62 as previously described, closing switch LS8, it energizes magnetic relay CR5 and completes a circuit'through magnetic valve IV4, admitting fluid under pressure to the lower end of cylinder I22 of the hoist for the unloading machine 32. See Figs. 16 and 17. This raises the hoist and loaded rack 22 a distance sufiicient to bring the lower shelf 21 to a position slightly above the level of the shuttle conveyor. The relay CR5 also completes a circuit leading to magnetic valve 3V3, causing the plunger I62 to return into the cylinder 28, as already described. The relay CR5 is of the delayed action type and is provided with a member I to hold the circuits described closed a sufficient time for the plunger to be returned and for the hoistand loaded rack to be raised the required distance. The hoist employed with the unloading machine is provided with a depending arm I59 secured to the head I24, and has a trip Ill near the lower end. The trip I1I when the hoist is raised to the position just described, engages and closes a switch LSIIl which completes a circuit to the magnetic valve 3V5, admitting fluid under pressure to the rear end of the cylinder ing magnetic relays CR6 and CR1 whichxcontrol switch 15, closing it and completing a circuit through magnetic valve IV3, which exhausts fluid from the hydraulic cylinder I22, allowing the hoist to settle and the shuttleconveyor to assume the load of the first row of loaded pallets on the a lower shelf 21 of the'rack 22'. The switch LS is similar to switch LS4, already described, and

the'arm I69 carried by the head I24 of the hoist is provided with notches I12 in which the stem I" of the switch L8 is adapted to drop and open the switch at the required intervals of lowering the hoist with the loaded rack 22.

When the pallets are lifted from the first shelves by the shuttle "conveyor when lowering the hoist, switch LSI2," carried by the shuttle conveyor is engaged and closed by one of the pallets completing a circuit through magnetic relay CR8 which in turn energizes-magnetic coil I'll closing the controlling switch to motor I14, which starts the motor and the conveyors to carry the pallets with their blocks out of the rack 22 and deliver them to the roller conveyor 33. It will be seen by a comparison of Figs. and 16 that the motor I'll must run in a direction opposite to motor 81. The blocks are thenre moved from the pallets by the hoist 34 and the pallets are returned by the roller conveyor to the block making machine III.

As the pallets travel over the stationary conveyor they engage and close switch LSI3, mounted on the stationary conveyor frame,- which enthe last, or uppermost shelf 21, a trip I16 on 2'. the head I24 engages and closes a switch LSI5 completing a circuit to magnetic valve 3V5 which admits fluid tothe forward end of hydraulic cylinder I I8, thus causing its plunger II9 to be retracted, together with the shuttle conveyor, returning the latter to its original position first described. v It will be understood that, in starting an operation as hereinbefore described, the switch LS3 at the end of the shuttle conveyor on the loading machine 3| should be closed manually to raise the hoist and rack 22 to a position to begin loading the rack and also switch LS9 should be closed to energize magnetic valve 3V4 and cause the shuttle conveyor to be moved to its extended position. It will also be necessary, of course, to hold the unloading machine 32 and its associated hoist out of operation until the first loaded rack 22 has made a complete circuit of the kiln and i has returned to the opening 29 in position in chine. Thepallets being lowered on to the racks and the racks on to the support by means of the hydraulic hoist insures that they will be handled gently and no blocks broken in loading. Further, the carrying of the racks around .the kiln on the rotary support eliminates all danger of jostling and jarring the racks and the breaking of blocks for that reason. It will also be apparent that I have eliminated the necessity of manual handling of the blocks or the racks from the time the.

blocks are freshly made until unloaded from the racks.

I wish it to be understood that I do not desire I machine for handling pallets bearing concrete. blocks comprising a stationary conveyor, a shuttle conveyor adapted to telescope within the stationary conveyor and to be extended beyond the stationary conveyor, a stationary conveyor frame, a supporting track for the shuttle conveyor mounted on the stationary conveyor frame, I means included in the stationary conveyor for delivering pallets to the shuttle conveyor when extended, a rack having a. plurality of superposed lateral shelves on which the pallets are loaded, a hydraulic hoist for the rack, control means for the hoist operative responsive to the delivery of pallets to the shuttle conveyor and adapted to position the successive shelves beneath the shuttle conveyor and to raise the rack for the shelves to engage the pallets and lift them oil the conveyor, and other control means operative responsive to raising the hoist to its highest position to retract the shuttle conveyor from the rack and lower the hoist and the rack.

2. In apparatus of the character described, a machine for handling pallets bearing concrete blocks comprising a stationary conveyor, a shuttle conveyor adapted to telescope within the stationary conveyor and to be extended beyond the stationary conveyor, a stationary conveyor frame, a supporting track for the shuttle conveyor mounted on the stationary conveyor frame, means included in the stationary conveyor for delivering pallets to the shuttle conveyor when extended, a rack having a plurality of superposed lateral shelves onwhich the pallets are loaded. a. hydraulic hoist for the rack, control means for the, hoist operative responsive to the delivery of pallets to the shuttle conveyor and adapted to position the successive shelves beneath the shuttle conveyor and to raise the rack for the shelves to engage the pallets and lift them off the conveyor, other control means operative responsive to raising the hoist to its highest position to retract the shuttle conveyor from the rack and lower the hoist and rack, a rotary support disposed to receive the rack as it is lowered by the hoist, a hydraulic cylinder and plunger for imparting intermittent rotary motion to the support, and .control means for the hydraulic cylinder operative responsive to lowering the hoist toits lowest position. v

3. In apparatus of the character described a machine for handling pallets bearing concrete blocks comprising a stationary conveyor including movable elements adapted to Support and move the blocks, a. shuttle conveyor adaped to telescope within the stationary conveyor and to be extended beyond the stationary conveyor, 9,

delivered on pallets from the block making ma- (5 supporting track for the shuttle conveyor disamass-r posed beneath the stationary conveyor, a rack having a plurality of superposed lateral shelves on which the pallets are loaded, a. hydraulic hoist for the rack, control means for the hoist operative responsive to the delivery of pallets to the shuttle conveyor and adapted to position the successive shelves beneath the shuttle conveyor and to raise the rack for the shelves to engage the pallets and lift them 011 the conveyor. other control means operative responsive to raising the hoist to its highest position to retract the shuttle conveyor from the rack and lower the hoist and the rack, a rotary support disposed to receive the rack ash. is lowered by the hoist, a hydraulic cylinder and plunger for imparting intermittent rotary motion to the support, control means for the hydraulic cylinder operative responsive to lowering the hoist to its lowestposition, and stop means to limit the motion imparted to the rotary supp rt. a

4. In apparatus of the character described, a machine for handling pallets bearing concrete blocks comprising a rack for receiving the pallets, a stationary conveyor having movable elements for moving the pallets, a shuttle conveyor adapted to telescope in the stationary conveyor and to extend outwardly therefrom and having movable elements adapted to deliver pallets onto the rack, and means operative responsive to complete loading of the rack to move the shuttle conveyor relative to the stationary conveyor.

5. In apparatus of the character described, a

machine for handling concrete blocks comprising a stationary conveyor for the blocks, a rotary support, a multiplicity of racks for the blocks adapted to be carried by the support, mechanism for receiving the blocks from the stationary conveyor and for loading the racks, mechanism operative responsive to complete loading 01' each rack for lowering the rack onto the support, mechanism operative responsive to lowering the rack for imparting rotary motion to the support, and other mechanism for unloading the racks after they have passed around the support.

6. Apparatus for" conveying and handling molded products comprising a circular movable support, a plurality of racks adapted to rest on the support and be carried thereby, mechanismior loading the molded products on the racks, mechanism for lowering the racks onto the support as they are completely loaded, other mechanism for unloading the products from the racks after they have passed around the support, control means for the loading mechanism operative responsive to the delivery 01' products thereto, means operative responsive to lowering of each rack onto the support for moving the support into position to place an empty rack in front of the loading mechanism and a loaded rackin front of the unloading mechanism, and control means for starting the unloading mechanism operative responsive to movement of the support.

.7. Apparatus for handling and conveying concrete blocks from a block making machine in which the blocks are delivered on pallets from shuttle conveyor disposed to move outwardly into the rack to load it and to telescope into the stationary conveyor, a hydraulic cylinder for moving the shuttle conveyor inwardly out oi the rack and control means for the hydraulic cylinder operative responsive to complete loading of the rack.

8. Apparatus according to claim 7 in which the rack is provided with a plurality of superposed shelves, a hydraulic hoist for raising the rack successively as each shelf is loaded, and control means for the hydraulic hoist operative responsive to loading the shelves.

9. Apparatus according to claim 7 in combination witha rotary support for the racks and means to rotate the support stepwby step "responsive, to complete loading and subsequent lowering of the racks. g

.10. Apparatus for handling and conveying concrete blocks from a block machine in which the blocks are delivered on pallets from the machine for loading onto and unloading iromracks in a circular kiln, comprising a rotary support for the racks, mechanism for receiving the loaded pallets from the machine and loading them. on the racks, control means for the operation of the rack loading mechanism operative responsive to delivery of pallets thereto, mechanism for lower ing the racks onto the support as they are completely loaded and means to impart intermittent rotary motion to the rotary support operable responsive to lowering the racks onto the. support.

11. Apparatus for handling and conveying concrete blocks from a block machine in which the blocks are delivered on pallets from the machine for loading onto and unloading from racksin a circular kiln,comprising a rotary support for the racks, mechanism for receiving the loaded pallets from the machine and loading them on the racks, control means for the operation of the rackloading mechanism operative responsive to delivery of pallets thereto, mechanism for lowering the racks onto the support. asthey are completely loaded, means to impart intermittent rotary motion to the rotary support operable responsive to lowering racks onto the support, a rack unloading machine disposed alongside the loading machine in position to unload the racks after they have passed around the kiln, and control means for starting the unloading machine operative responsiveto movement of the rotary support.

12. Apparatus according to claim 11 in which the racks are each provided with a plurality of superposed shelves, hoists disposed under the rotary support in front of the loading and u.nloading machine, and control means for the hoists operative responsive to engagement with pallets 0n the loading and unloading machine.

13. Apparatus for handling and conveying concrete blocks from a block machine in which the blocks are delivered. on pallets from the machine for loading onto and unloading from the machine comprising a. conveyor for receiving the pallets from the machine and including means for supporting and moving the pallets away from the machine, a motor for driving the conveyoncontrol means for the motor responsive to movement of pallets from the block making machine and disposed to eilect movement of the conveyor the distance occupied by a pallet, a rack on which the block carrying pallets are loaded, a

the racks in a circular kiln, comprising a rotary support in the kiln, a plurality of racks ior'the blocks adapted to rest on the rotary support, a. machine for loading the racks disposed in front of the kiln, mechanism for lowering the racks onto the support as they are completely loaded, a. hydraulic cylinder and plunger for imparting intermittent rotary motion to the support, control means for the cylinder operative responsive to the lowering of a rack onto the support, stop mean for the rotary support to limit its move- ROBERT M. GRAY.

14 nnrnnnncns crmn The following references are of record in the file of this patent:

5 UNITED STATES PATENTS Number Name Date 504,212 Ghere et a1. Aug. 29, 1893 1,100,374 Hughes June 16, 1914 2,150,211 Edwards Mar. 14, 1939 Billman Feb. 8, 1944 

